Cellulose-acetate solution



I 7 methylene chlorid (dichlormethane).

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entree snares GUSTAV w. comm, or EosTon, MASSACHUSETTS, Assrenon To THESLACHEB cnErrIcAE COMPANY, or ETH manor, NEW JERSEY, A co AND PORA'IION@35 NEW Y0.

PATENT @FFIQE.

ROESSLER CELLULOSE-ACE'IA'IE SOLUTION.

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No Drawing.

To all wiwm it may concem:

Be it known that I, GUSTAV W. GOERNER, citizen of the United States ofAmerica, and resident of Boston, in the county of Suffolk and State ofMassachusetts, have invented new and useful Improvements in Cellulose-A-cetate Solutions, of which the following is a specification. I

My invention relates to Solutions of cellulose esters of the monobasicfatty acids, of which cellulose acetate in its various forms andmodifications is technically and commercially the most conspicuousexample, and conslsts in a new composltion of matter, namely, thesolution of such an. ester in I use the word solution in a comprehensivesense as denoting mutual extension of reciprocally miscible substances,and ncludin the physical conditlon of plasticity.

dhe cellulose acetate produced by reaction of fibrous cellulose withacetic anhydrid and glacial acetic acid in the presence of sulfuricacid, acting as a catalyst, and whlch is characterized by solubility inchloroform, I have discovered to be equally soluble-or substantially assolublein methylene chlorid. Acetates which difler from the acetateabove mentioned, in that their modification manifests itself by inferiorsolubility in chloroform, to the border-conditlon of plasticity,therein, behave similarly 1n methylene chlorid.

But, with respect to these acetates, I have discovered that the additionto the methylene chlorid of a moderate proportion of either ethyl ormethyl alcohol-a bout 5 by weight, on the methylene chlorid, malntainsthe efli'ciency of the solvent as such,

and provides a composite liquid in Which acetates solvent only to aninferior degree in methylene chlorid are as freely solvent as is theacetate first above mentioned in methylene chlorid alone.

The proportion of alcohol in the mixture which serves as a solvent insuch cases is variable, provided the methylene chlorid be thepreponderant ingredient. The maxi- Specification of Letters Patent.

Patented July 12, rear.

Application filed June 9, 1920. Serial No. 387,677.

mum limit for the proportion of alcohol, conslstent with thesolvent-function of the mixture, is alsovariable, but can readily bedetermined empirically with any given acetate presented for solution. Apoint will be reached when the proportion of alcohol is too large, andthis practical maximum for the speclfic instance in hand is announced bythe refusal or reluctance of the acetate to go lnto solution. Theminimum limit for the alcohol proportion is likewise variable, andascertalnable by similar empirical test. In such lnstances as have beenobserved, the maximum of alcohol is indicated to be in the neighborhoodof 10% on the methylene Clglgld, the minimum in the neighborhood 0 0-Solutions of cellulose esters, exemplified by the acetate, in methylenechlorid, constitute compositlonsof matter of which the uses andadaptations are similar to those of known solutions of cellulose esters;these uses and adaptations need not, therefore, be enlarged upon.

What I claim, Letters Patent is:

l. A solution of a cellulose ester of a monobaslc fatty acid in asolvent comprisng methylene chlorid aS the predominant ingredient.

2. A solution of a cellulose ester of a monobasic fatty acid inmethylene chlorid.

3. A solution of a cellulose ester of a monobasic fatty acid in asolvent comprising methylene chlorid and alcohol, the former inpredominance.

4. A solution of cellulose acetate in a solvent comprising methylenechlorid as the predominant ingredient.

5. A solution of cellulose acetate in methylene chlorid.

6. A solution of cellulose acetate in a solvent comprising methylenechlorid and alco hol the former in predominance.

igned by me at Boston, Massachusetts, this seventh day of June, 1920.

and desire to secure by

